Critically evaluated rate coefficients for free‐radical polymerization, 1. Propagation rate coefficient for styrene

Abstract

SUMMARYPulsed-laser polymerization (PLP) in conjugation with molecular weight distribution (MWD) measurement has emerged as the method of choice for determining the propagation rate coefficient k, in free-radical polymerizations. Detailed guidelines for using this technique (including essential internal consistency checks) and reporting the results therefrom are given by the authors, members of the IUPAC Working Party on Modeling of kinetics and processes of polymerization. The results for PLP-MWD k, measurements from many laboratories for bulk free-radical polymerization of styrene at low conversions and ambient pressure are collated, and are in excellent agreement. They are therefore recommended as constituting a benchmark data set, one that is best fitted by (the confidence ellipsoid for the Arrhenius parameters is also given). These benchmark data are also used to evaluate the merits of several other methods for determining k,; it is found that appropriately calibrated electron paramagnetic resonance spectroscopy appears to yield reliable values of k, for styrene.

The role of mid‐chain radicals in acrylate free radical polymerization: Branching and scission

“…k p is determined by the IUPAC-recommended technique pulsed laser polymerization-size exclusion chromatography (PLP-SEC), in which the propagation rate is deduced from the characteristic molecular weight pattern that is produced upon laser initiation at a constant pulse rate. [20][21][22][23] Although PLP-SEC is a reliable method that works in a broad range of conditions, only little k p data was received from experiments above room temperature. [24][25][26] Although, not unlike the discussion about the monomer reaction order x, other factors such as transfer to monomer were discussed, 24 Asua and coworkers soon made the connection to the transfer to polymer reactions.…”

Critically evaluated rate coefficients for free-radical polymerization Part 6: Propagation rate coefficient of methacrylic acid in aqueous solution (IUPAC Technical Report)

“…Critical evaluation of k p data from PLP-SEC experiments performed in several laboratories worldwide resulted in a series of papers which report benchmark values of k p for styrene [3], methacrylate monomers [4][5][6], and butyl acrylate homopolymerizations [7]. The underlying k p data have been deduced from experiments in which different PLP and SEC set-ups have been used for one and the same monomer.…”

The influence of intermediate radical termination and fragmentation on controlled polymer synthesis via RAFT polymerization

“…A viable approach, the pulsed-laser polymerization [23] is yet to be applied for the RAFT kinetic parameters, k add and k frag . The kinetic coefficients, however, can be deduced from experimental data, such as rate of polymerization and average molecular weight in combination with a kinetic scheme.…”